Martin Sandler on C-Span, 6th November 2013:

‘I’ll tell you one thing: I found articles — not tripped in publications but in very sophisticated publications — saying, ‘Forget Lyndon Johnson, forget the CIA, forget Fidel Castro—Mossad killed JFK because they were upset by what he had done to Ben-Gurion.’ So you see, we drop a few bombs like this in this book, unproven…’

The Letters of John F. Kennedy, by Martin Sandler, p. 333-341:

   ‘In March 1992, Representative Paul Findley of Illinois, wrote in the Washington Report on Middle Eastern Affairs, “It is interesting. . . . to notice that in all the words written and uttered about the Kennedy assassination, Israel’s intelligence agency, the Mossad, has never been mentioned.” Two years later in his book Final Judgment, author Michael Collins Piper actually accused Israel of the crime. Of all the conspiracy theories, it remains one of the most intriguing.

    What is indisputable is that, although it was kept out of the eye of both the Press and the Public, a bitter dispute had developped between Israeli prime minister David Ben-Gurion who believed that his nation's survival depended on it attaining nuclear capability and Kennedy who was vehemently opposed to it. In May 1963, Kennedy wrote to Ben-Gurion explaining why he was convinced that Israel's pursuit of nuclear weapons capability was a serious threat to world peace.’

Michael Collins Piper’s book Final Judgment:
https://b-ok.org/book/2880748/421ce2?dsource=recommend

Sources:

https://www.c-span.org/video/?c4547313/user-clip-jfk-gurion-mossad-dimona

https://pascasher.blogspot.com/2020/09/rappel-sur-le-seul-ouvrage-et-la-seule.html